Resilient devices for temporarily binding and gripping the edge of materials

ABSTRACT

A device for gripping the marginal edge of materials is provided which takes the form of an elongated continuous section of resilient material. The section has a pair of legs having gripping surfaces at one end thereof, and interconnected at the other end by a looped shaped web disposed between the legs. The legs, at their other ends, are mounted for pivotal movement. Upon separating movement of the legs at their gripping ends, the loop shape web flattens and a gripping force is generated as a reaction thereto. In certain embodiments, the device is shiftable to accommodate a multiplicity of thickness ranges of material.

United States Patent [191 McNichol RESILIENT DEVICES FOR TEMPORARILY'BINDING AND GRIPPING THE EDGE OF MATERIALS [76] Inventor: David H.McNichol, 1325 S. Belvoir Blvd, Euclid, Ohio 44121 [58] Field of Search24/67 R, 67.3, 67.9, 81 MC, 24/81 PC, 243 P, 248 PC, 255 BC, 255 PC,

255 P, 255 TV, 255 TZ, DIG. 8, 260, 255

SL,137 R, 67.11; 132/50 A, 50 B [56] References Cited UNITED STATESPATENTS 1,197,314 9/1916 Wells 24/67.3 2,166,460 7/1939 Burns 132/50 B2,532,674 12/1950 Nelsen 24/137 R Nov. 5, 1974 2,869,210 1/1959Schneider 24/67.3 3,308,831 3/1967 Kritske 24/248 PC 3,348,275 10/1967Lawrence 24/137 R Primary ExaminerFrancis K. Zugel AssistantExaminer-Kenneth J. Dorner [5 7 ABSTRACT A device for gripping themarginal edge of materials is provided which takes the form of anelongated continuous section of resilient material. The section has apair of legs having gripping surfaces at one end thereof, andinterconnected at the other end by a looped shaped web disposed betweenthe legs. The legs, at their other ends, are mounted for pivotalmovement. Upon separating movement of the legs at their gripping ends,the loop shape web flattens and a gripping force is generated as areaction thereto. In certain embodiments, the device is shiftable toaccommodate a multiplicity of thickness ranges of material.

10 Claims, 14 Drawing Figures 1 RESILIENT DEVICES FOR TEMPORARILYBINDING AND GRIPPING THE EDGE OF MATERIALS BACKGROUND OF THE INVENTIONThis invention relates generally to edge binding and gripping strips forthe edges of material, and more particularly to devices for releasablysecuring stacked looseleaf sheets of material, such as paper, togetherat one marginal edge of the stack.

One of the most common types of temporary edge bindings for reports,sales literature, catalogs, etc. has been a resilient plastic stripwhich in cross section has a solid, essentially straight across end webfrom which a pair of legs project. The legs converge or angle inwardlycoming intocontact at their extreme ends. The resiliency of the materialused in the legs and end web, as extruded, hold the ends of the legstogether and when the legs are separated and the stacked sheets of paperinserted therebetween, this resiliency will cause the legs to tend toreturn to their original as extruded shape and to grip the insertedstack of papers, temporarily binding their edges.

While this type of edge binding in general works quite well. it doeshave certain undesirable aspects. One of these is that it has a fixed,non-adjustable profile thickness which results in unnecessary bulk whengripping just a few sheets; i.e., the device is formed to stationaryprofile thickness which is equal to the thickness required forgrippingthe maximum number of sheets and must retain that profilethickness even when less than the maximum number of sheets areinserted.This means that the gripped edge of the stack has a very wide,cumbersome profile with a minimum number of sheets.

SUMMARY OF THE INVENTION.

DESCRIPTION OF THE DRAWING FIG. I is a perspective view showing an edgebinding striputilized to bind one edge of a stack of sheets of looseleafmaterial.

FIG. 2 is a sectional view taken substantially along the planedesignated by the line 2-2 of FIG. 1, showing the cross sectionconfiguration of a conventional prior edge binding strip.

FIGS. 20, 2b and 2c are sectional views taken substantially along theplane designated by the line 2-2 of FIG. 1, showing the cross-sectionconfiguration of one embodiment of an edge binding strip according tothis invention, showing various states of expansion to accommodatedifferent thicknesses of stacked sheets.

FIGS. 3a and 312 show the cross-section configuration of yet anotherembodiment of an edge binding strip according to this invention whichcan be expanded to accommodate various ranges of thicknesses of sheetsof stacked material.

FIGS. 4a and 4b show the cross-section configuration of yet anotherembodimentof an edge binding strip according to this invention which canbe expanded to accommodate various ranges of thicknesses of sheets ofstacked material.

FIGS. 5a and 5b and 5c show the cross-sectional configuration of still afurther embodiment of this invention which can be expanded from thenormal position to two expanded positions.

FIGS. 6a and 6b show the cross-sectional configuration of still afurther embodiment of an edge binding strip according to this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawing,FIG. 1 shows in perspective a stack of sheets of looseleaf papertemporarily bound together at one marginal edge of the stack by means ofan edge binding strip. The strip depicted is not intended to representany specific cross-sectional configuration, but rather depicts a mannerin which strips of the prior art and the present invention are utilized.This figure forms a basis for illustrating the crosssectionalconfigurations of the prior art and the present invention.

Referring now to FIG. 2, the cross-sectional configuration of oneconventional prior art binding strip is shown. (In this figure as wellas the other sectional figures, cross hatching has been eliminated forclarity .of illustration.) The strip is conventionally made of resilientplastic, having a pair of legs 10 joined at one end thereofby anessentially straight and continuous solid web section 12. In its normalor as-extruded condition, the legs 10 come together as-shown in solidlines in FIG. 2.

In order to utilize the device, the legs 10 are spread sufficiently toaccommodate the thickness of the stacked sheets, and the sheets areinserted therein. The legs are then released and will grip a stack ofsheets due to the inherent resiliency of the legs, causing them to tendto return to the configuration as shown in FIG. 2. The thicker the stackof sheets the wider the legs must be spread until they reach a maximumposition essentially as shown in dotted lines in FIG. 2, wherein thelegs are substantially parallel with each other. If the legs are spreadany further, they will not properly engage the stack of sheets so thisparallel relationship is essentially the maximum open limit. In thismaximum open condition, the width between the legs as they engage thepaper is substantially the same as the width of the legs where they arejoined by'the web 12. This width or thickness being designated by thedimension a in FIG. 2.

It will be noted from an examination of FIG. 2 that even in itscompletely closed position, as shown in solid line, and without anysheets beinggripped between the legs, the maximum profile thickness ofthe device is equal to the a dimension. Thus, even with very few sheets,the profile thickness of the strip is unchanged, in that it isdetermined by the fixed web 12 of this prior art configuration. Thethickness never exceeds this a dimension since when the spread of thelegs reaches this a dimension, the strip has reached its capacity.

This fixed maximum profile thickness, when gripping a very thin stack ofsheets detracts from the desirability because of the inherent surplus ofbulk, or thickness. This undesirable feature is substantially overcomeby strips formed according to the present invention.

Referring now to FIGS. 2a, 2b and 2c, the cross sectional configurationof one embodiment of a binding strip according to this invention isshown. The binding strip is formed of a resilient plastic material suchas styrene. (Of course, other resilient plastic or metal could be used.)The strip has a pair of legs 20 which have serrated gripping surfaces 22at one end thereof. At the opposite ends of the legs 20 are a pair ofabutting flat projections 24. The legs 20 are joined by looped shapedweb 26 which web has a pair of straight arm portions 28 normally incontact or in close proximity with the legs 20 and an arcuate connection30.

The device is shown in FIG. 2a in its completely closed or normallyunused position without any sheets between the legs in which conditionthe gripping surfaces 22 are abutting. This is the configuration inwhich the strip is normally formed or the as-extruded shape. FIG. 2bdepicts the strip engaging a stack of sheets of minimal thickness, FIG.20 depicts the strip engaging essentially the maximum thickness ofstacked sheets.

As can best be seen in FIG. 2a, the maximum profile thickness is acrossthe strip where the legs are joined to the web and designated by thedimension b. The legs gradually converge or angle inwardly from thismaximum width to their other extreme ends which are in contact with eachother. The inherent resiliency of the plastic maintains the strip inthis as-formed shape shown in FIG. 2a with the gripping surfaces 22 incontact with each other and the abutting projections 24 also in contactwith each other. It will be noted that the dimension b is substantiallyless than the dimension a. (FIGS. 2 and 2a, 2b and 2c are drawn toessentially the same scale.) In fact, the dimension can be as much as 30percent greater than the dimension b for devices of the same maximumcapacity as will become apparent presently.

Referring now to FIG. 2b, when just a few sheets are gripped between thelegs 20, the legs flex resiliently to grip the sheets in a mannersimilar to the device of the prior art, and there is no appreciableincrease in the profile thickness of the binding strip. However, as moreand more sheets are added, a different type of action takes place. Thistype of action is characterized by the legs pivoting against each otherat the ends of their abutting projections 24 as shown in FIG. 20, with acorresponding flattening and rearward deformation of the curved portion30 and the straight portions 28 of the web 26. This results in agripping action by the legs generated, at least, in part as a functionof the resiliency and deformation of the web tending to pull the legstogether as a reaction to the separating of the legs. This allows thelegs 20 to expand to a thickness wider than the b dimension and in factexpand as much as 30 percent beyond this dimension to the dimension cwhich is substantially equal to the a dimension shown in FIG. 2. At thispoint, the legs have reached their maximum open capacity beyond whichthey will not effectively engage the stacked material. However, it isnot until an appreciable thickness of stacked sheets have been grippedbetween the legs, that the legs in fact start expanding past the bdimension, and they do not actually reach the maximum 0 thickness untilthe maximum number of sheets are gripped therebetween. Thus, an edgebinding strip is provided which has a much thinner profile thicknesswhen just a few sheets are secured and yet can expand beyond thisminimum to accommodate a greater number of sheets while maintaining thethinnest possible profile for the given thickness of sheets beingsecured.

Referring now to FIGS. 3a and 3b, another embodiment of an edge bindingstrip according to this invention is shown. This embodiment is actuallyadjustable or shiftable to accommodate two different ranges of thicknessof stacked sheets. FIG. 3a shows the cross sectional configuration ofthe strip in its as-formed condition suitable for use with the thinnerrange of thickness and FIG. 3b shows the device shifted to its positionfor accommodating the thicker range.

In this embodiment, a pair of legs 32 are provided which have grippingsurfaces 31 at one end thereof similar to the gripping surfaces 22 ofthe previous embodiment. The legs 32 terminate at their opposite ends inprojections having abutting points 33 defined by rearwardly directedsloped surfaces 34 and forwardly directed sloped surfaces 35. A webmember 44 similar in size and configuration to the web 26 of thepreviously described embodiment joins the legs 32 at their ends oppositefrom the gripping surfaces 33. A pointed wedge member 36 is carried by asecond web member 38 interconnecting the legs 32 and located outside theconfines of the legs. The wedge 36 has a pair of forwardly directed camsurfaces 40 and a pair of rearwardly directed cam surfaces 42 whichtogether define laterally directed points.

In the thinner, as-extruded configuration as shown in FIG. 3a, theabutting points 33 of the legs 32 also rest against the cam surfaces 40of the wedge 36 and the gripping edges 31 of the legs 32 are in contactwith each other. When the legs are separated to accommodate a relativelythin stack of sheets, the inherent resiliency of the legs provides thegripping action as in the previously described embodiment as shown inFIG. 2b. As the legs are further separated, the legs will pivot againstthe abutting points 33 allowing the legs to continue to open and causinga flattening of the web 44 in much the same manner as of the previousembodiment, and grip until a maximum has been reached, this maximumbeing substantially thicker than the device in its closed position shownin FIG. 3a.

If it is desired to accommodate a thicker range of stacked sheets, thedevice is shifted to the position shown in FIG. 3b. This is done bypushing the wedge 36 toward the web 44 which will cause the cam surfaces40 to separate the sloping surfaces 34, this movement continuing untilthe points on the wedge 36 have passed the points on the legs 32 and theforward surfaces 35 on the legs engage the rear cam surfaces 42 on thewedge. This portion is shown in FIG. 3b with dimension d being the newprofile thickness which can now accommodate approximately I00 percentgreater thickness of sheets than b. As this thickness of sheetsincreases, the further spreading of the legs will be accomplished by theend surfaces 35 of the legs pivoting against the cam surfaces 42 with acorresponding flattening of the loop web 44 which will allow the legs tospread open still further to the overall profile thickness e shown inFIG. 3b. Thus, with the device shown in FIGS. 3a and 3b, two separatethickness ranges of stacked sheets can be provided for in a singledevice, thus eliminating the necessity of carrying two different sizestrips in stock.

FIGS. 4a and 4b show the cross section configuration of anotherembodiment of an edge binding strip which also is shiftable to twopositions for accommodating two different size ranges of stacked sheets.In this configuration, a pair of legs 46 is provided which have grippingsurfaces 47 similar to those in the previously described embodiments.The legs 46 also have abutting surfaces 48 at the opposite ends thereofeach of which surfaces 48 has provided therein a notch 50. A loop shapedweb 52,is disposed between the legs 46 and interconnects the legs. Awedge 54 is carried by the loop 52 and extends toward the abuttingsurfaces 48. The wedge 54 has a pair of points 56 on opposite sidesthereof. In the narrower configuration as shown in FIG. 4a, the grippingedges 47 are in contact with each other as are the abutting surfaces 48.In this configuration, the device operates substantially as describedwith respect to FIGS. 2a, 2b and 2c. This constitutes the position forreceiving the narrow thickness range of stacked sheets.

When a wider thickness range is desired, the loop web 52 is pushedtoward the abutting surfaces 48 which will cause the wedge 54 toseparate surfaces 48 until the points 56 of the wedge engage the notches50. This then constitutes the position for receiving the thicker rangeof stacked sheets as shown in FIG. 4b. The gripping edges 47 areseparated as shown therein which constitutes the thinnest stack ofsheets which can be accommodated and the legs open from there to themaximum. Thus, this embodiment, as the previous embodiment, can accept awide range of thickness of stacked sheets.

The embodiment shown in FIGS. 5a, 5b and 5c is quite similar to thatshown in FIGS. 4a and 4b except that it can be shifted to threedifferent thickness range accepting positions. In this embodiment, thelegs 60 are provided with spaced rear surfaces 62. These surfaces 62have teeth-like projections 64 extending therefrom and as shown in FIG.5a are normally in contact. A wedge 66 is provided carried bya loopshaped web 67. The wedge 66 is barbed in shape having a central notch 68and an end notch 70. In the position shown in FIG. 5a, the device ispositioned to receive the thinnest range of stacked sheets. By movingthe wedge 66 in a position as shown in FIG. 5b, the device is set toaccommodate an intermediate thickness range of sheets and by moving thedevice to the position shown in FIG. 5c, the maximum thickness range ofsheets is provided for. This device operates in a manner very similar tothat shown in FIGS. 4a and 4b.

Referring now to FIGS. 6a and 6b, still another embodiment of a deviceof this present invention is shown. This device is quite similar to thatshown in FIGS. 2a, 2b and except that the legs and web are somewhatdifferently shaped. In this embodiment, a pair of legs 72 are provided,having flat end surfaces 74 connected by a loop shaped web 76. In thisembodiment the legs 72 diverge outwardly from the end surfaces 74 to acentral portion 78 and then converge inwardly to the gripping ends 80.Also, the web 76-is somewhat different in shape from the web shown inFIGS. 2a, 2b and 20. However, this device works quite similarly to thatdepicted in FIGS. 2a, 2b and 2c; i.e., initially for a thin stack ofsheets, the resiliency of the legs will provide the gripping action andas the thickness of the stacked sheets increases, there will be apivoting action about the abutting surface with a flattening of the webto provide at least in part the gripping action.

While several embodiments of the invention have been shown anddescribed, with certain modifications it is understood that othermodifications may also be made. For example, the loop shaped web maytake on many different configurations; indeed the term loop as usedherein includes any non-linear interconnection which can change shaperesponsive to movement of the legs such as an arcuate shape, a tentshape, etc.

What is claimed is:

l. A device for securing, binding, or gripping sheet materials at amarginal edge of said materials, comprising a continuous section ofresilient material having a pair of legs and connecting means joiningsaid legs at one end portion of said legs, said legs extending from saidconnecting means and terminating in cooperating material engaging endportions adapted to clampingly secure the materials therebetween, saidconnecting means including a loop-shaped web member interconnecting saidlegs and disposed therebetween, said device being formed with surfacemeans at the end thereof remote from the material engaging end portionsof the legs including a pair of opposed separable surfaces at the endsof the legs, said surface means being normally in mutual engagement anddisposed to provide pivotal movement of each of the legs, and togenerate a gripping force between said legs in reaction to separatingmovement of said legs at their materialgripping end portions, saidloop-shaped web member being disposed between said surfaces and saidmaterial engaging end portions of said legs.

2. The invention as defined in claim 1 wherein said legs are inengagement with each other at their end portions remote from saidgripping end portions and pivotal against each other.

3. The invention as defined in claim 1 wherein the outer surface of saidlegs become progressively closer together from the remote end to thegripping end portions.

4. The invention as defined in claim 1 wherein the looped shape web hasa pair of generally straight arms each in contact with one leg and anarcuate portion interconnecting said arms.

5. The invention as defined in claim 1 wherein each leg divergesoutwardly from the remote end portion to an intermediate portion andthence inwardly.

6. The invention as defined in claim 1 further characterized by shiftingmeans to selectively move and retain the normally engaging surfacesoutwardly from each other whereby to expand the capacity of said device.

7. The invention as defined in claim 6 wherein said shifting meansincludes a wedge member disposed to selectively separate the remote-endportions of said legs and provide a fulcrum for pivoting.

8. The invention as defined in claim 7 wherein said wedge member iscarried by the loop-shaped web within the loop.

9. The invention as defined in claim 7 wherein said wedge member iscarried by a second web member external of the legs.

10. The invention as defined in claim 6 wherein said shifting meansincludes means to shift and retain the pivot point to a plurality ofdiscrete positions outwardly from the normal position.

1. A device for securing, binding, or gripping sheet materials at amarginal edge of said materials, comprising a continuous section ofresilient material having a pair of legs and connecting means joiningsaid legs at one end portion of said legs, said legs extending from saidconnecting means and terminating in cooperating material engaging endportions adapted to clampingly secure the materials therebetween, saidconnecting means including a loop-shaped web member interconnecting saidlegs and disposed therebetween, said device being formed with surfacemeans at the end thereof remote from the material engaging end portionsof the legs including a pair of opposed separable surfaces at the endsof the legs, said surface means being normally in mutual engagement anddisposEd to provide pivotal movement of each of the legs, and togenerate a gripping force between said legs in reaction to separatingmovement of said legs at their material-gripping end portions, saidloopshaped web member being disposed between said surfaces and saidmaterial engaging end portions of said legs.
 2. The invention as definedin claim 1 wherein said legs are in engagement with each other at theirend portions remote from said gripping end portions and pivotal againsteach other.
 3. The invention as defined in claim 1 wherein the outersurface of said legs become progressively closer together from theremote end to the gripping end portions.
 4. The invention as defined inclaim 1 wherein the looped shape web has a pair of generally straightarms each in contact with one leg and an arcuate portion interconnectingsaid arms.
 5. The invention as defined in claim 1 wherein each legdiverges outwardly from the remote end portion to an intermediateportion and thence inwardly.
 6. The invention as defined in claim 1further characterized by shifting means to selectively move and retainthe normally engaging surfaces outwardly from each other whereby toexpand the capacity of said device.
 7. The invention as defined in claim6 wherein said shifting means includes a wedge member disposed toselectively separate the remote-end portions of said legs and provide afulcrum for pivoting.
 8. The invention as defined in claim 7 whereinsaid wedge member is carried by the loop-shaped web within the loop. 9.The invention as defined in claim 7 wherein said wedge member is carriedby a second web member external of the legs.
 10. The invention asdefined in claim 6 wherein said shifting means includes means to shiftand retain the pivot point to a plurality of discrete positionsoutwardly from the normal position.